Holding hands at the June 29 Radiohead concert in Los Angeles, the pair "were having so much fun," says a fellow concertgoer. "It was like you were watching a romantic comedy."

The 44-year-old comedian, says a source close to him, "is very happy."

As is McCarthy, who has been uncharacteristically mum about her new love. "I'm so brutally honest and tell people everything about my personal life, it's really hard not to," she told Access Hollywood, adding that Carrey is "an amazing person."

The couple have more than just a silly streak in common: Carrey has a daughter, 18-year-old Jane, with first wife Melissa Womer; McCarthy has a son, 4-year-old Evan, with director John Asher. (McCarthy and Asher filed for divorce last August.)

For now, the twosome seem focused on simply having a good time. "They were laughing and smiling," says an observer at the Radiohead concert. "They just look like such a great couple."

I like that they both have kids. They seem to really fit with one another. They must be cracking each other up all the time. Although he has been getting some flack for his latest hair do, I think it looks great on him. He looks younger to me now, but that could also just be the look of love.

I like them, they're like war buddies. They both seem to have been through the Hollywood ringer; smokin hot careers followed by long lulls and dissapointing career moves, up and down tabloid-fodder relationships, off-beat humor, they're both parents, etc.. They make sense to me. I hope they make it in the long haul.